At the same time we can't assume Bills is stronger or weaker based on the fact that only one has feats. Otherwise we could say that Krillin is stronger than the 11 other Gods because they are featless. Thus basing it off of GT Goku's strength, combined with the power of Shenron and decades going by, to me it almost certain Goku would win. Either is speculation but Goku winning seems a lot more plausible which is why I'm with him on this.